CT-guided localization of small pulmonary nodules using adjacent microcoil implantation prior to video-assisted thoracoscopic surgical resection.

OBJECTIVES: To describe and assess the localization of small peripheral pulmonary nodules prior to video-assisted thoracoscopic surgical (VATS) resection using the implantation of microcoils. METHODS: Ninety-two patients with 101 pulmonary nodules underwent computed tomography (CT)-guided implantation of microcoils proximal to each nodule. Patients were randomly assigned to undergo entire microcoil or leaving-microcoil-end implantations. The complications and efficacy of the two implantation methods were evaluated. VATS resection of lung tissue containing each pulmonary lesion and microcoil were performed in the direction of the microcoil marker. Histopathological analysis was performed for the resected pulmonary lesions. RESULTS: CT-guided microcoil implantation was successful in 99/101 cases, and the placement of microcoils within 1 cm of the nodules was not disruptive. There was no difference in the complications and efficacy associated with the entire implantation method (performed for 51/99 nodules) versus the leaving-microcoil-end implantation method (performed for 48/99 nodules). All nodules were successfully removed using VATS resection. Asymptomatic pneumothorax occurred in 16 patients and mild pulmonary haemorrhage occurred in nine patients. However, none of these patients required further surgical treatment. CONCLUSIONS: Preoperative localization of small pulmonary nodules using a refined percutaneous microcoil implantation method was found to be safe and useful prior to VATS resection. KEY POINTS: • An increasing number of small, indeterminate pulmonary lesions need to be characterized. • Entire microcoil and leaving-microcoil-end implantation methods were described for nodule localization. • Adjacent microcoil localization prior to video-assisted thoracoscopic surgical resection involved minimal intervention. • Preoperative microcoil localization facilitates the definitive resection of small pulmonary nodules.

Quantitative Measurement of Cerebral Perfusion with Intravoxel Incoherent Motion in Acute Ischemia Stroke: Initial Clinical Experience.

BACKGROUND: Intravoxel incoherent motion (IVIM) has the potential to provide both diffusion and perfusion information without an exogenous contrast agent, its application for the brain is promising, however, feasibility studies on this are relatively scarce. The aim of this study is to assess the feasibility of IVIM perfusion in patients with acute ischemic stroke (AIS). METHODS: Patients with suspected AIS were examined by magnetic resonance imaging within 24 h of symptom onset. Fifteen patients (mean age was 68.7 ± 8.0 years) who underwent arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) were identified as having AIS with ischemic penumbra were enrolled, where ischemic penumbra referred to the mismatch areas of ASL and DWI. Eleven different b-values were applied in the biexponential model. Regions of interest were selected in ischemic penumbras and contralateral normal brain regions. Fast apparent diffusion coefficients (ADCs) and ASL cerebral blood flow (CBF) were measured. The paired t- test was applied to compare ASL CBF, fast ADC, and slow ADC measurements between ischemic penumbras and contralateral normal brain regions. Linear regression and Pearson's correlation were used to evaluate the correlations among quantitative results. RESULTS: The fast ADCs and ASL CBFs of ischemic penumbras were significantly lower than those of the contralateral normal brain regions (1.93 ± 0.78 αµm2/ms vs. 3.97 ± 2.49 αµm2/ms, P = 0.007; 13.5 ± 4.5 ml·100 g-1·min-1 vs. 29.1 ± 12.7 ml·100 g-1·min-1, P < 0.001, respectively). No significant difference was observed in slow ADCs between ischemic penumbras and contralateral normal brain regions (0.203 ± 0.090 αµm2/ms vs. 0.198 ± 0.100 αµm2/ms, P = 0.451). Compared with contralateral normal brain regions, both CBFs and fast ADCs decreased in ischemic penumbras while slow ADCs remained the same. A significant correlation was detected between fast ADCs and ASL CBFs (r = 0.416, P < 0.05). No statistically significant correlation was observed between ASL CBFs and slow ADCs, or between fast ADCs and slow ADCs (r = 0.111, P = 0.558; r = 0.200, P = 0.289, respectively). CONCLUSIONS: The decrease in cerebral blood perfusion primarily results in the decrease in fast ADC in ischemic penumbras; therefore, fast ADC can reflect the perfusion situation in cerebral tissues.